Sharpener assembly for a food slicer and related method

ABSTRACT

A sharpener assembly for a food slicer includes a rotatable frame with a sharpening member and a truing member operatively connected for rotation with the frame. The frame is mounted on a food slicer to place the sharpening member and truing member on opposed sides of a slicer knife. The frame is rotated to rotate the sharpening member and the truing member into contact with respective sides of the slicer knife.

TECHNICAL FIELD

[0001] The present invention relates to a sharpener assembly for a foodslicer and, more particularly, to a sharpener assembly configured forenabling pivotal movement of a sharpening wheel and a truing wheeltoward opposite sides of a knife of a food slicer.

BACKGROUND OF THE INVENTION

[0002] Typical food slicers have a base with a rotatable, circular ordisc-like slicing knife mounter thereon, a gauge plate for determiningthe thickness of the slice and a carriage for supporting the food as itis moved past the cutting edge of the knife during slicing. The cuttingedge of the knife tends to dull from use and therefore a sharpener isneeded to sharpen the knife to maintain a good cutting edge forefficient slicing. Sharpening stones are typically brought against theknife's cutting edge as the knife rotates in order to provide suchsharpening. A variety of sharpening devices have been used in the pastto provide such sharpening.

[0003] Many existing sharpening devices suffer from using complexarrangements to convert a rotational movement into two translationalmovements. Other existing sharpening devices require two steps, a firstin which a sharpening wheel or stone is brought into contact with oneside of the knife to sharpen, and a second in which a truing wheel orstone is brought into contact with the opposite side of the knife todebur the knife edge.

[0004] U.S. Pat. No. 5,591,072 which is assigned to the assignee of thepresent application provides a sharpening device which overcame theproblem of having to move the sharpening device between an inactive orstowed position and an active or sharpening position. However, theconstruction provided is relatively complex and includes a large numberof parts adding to the expense of manufacture. Canadian Patent No.630,702 describes a slicer with a knife sharpener which includessharpening wheels which can be positioned on opposite sides of a knifefor sharpening, but as mentioned above, requires the sharpener tonormally be stored in an inactive position when not in use and in suchinactive position the sharpening wheels are not positioned on oppositesides of the knife. Further, the sharpener requires two handles to beoperated in order to sharpen the slicer knife.

[0005] Another disadvantage of known knife sharpeners is that thesharpening stones or wheels typically need to be more abrasive than thetruing stones or wheels used. This requirement adds to parts cost ofsharpeners and requires a more exacting manufacturing process in orderto assure that the wheels of appropriate abrasiveness are placedproperly during manufacture.

[0006] Further, certain food slicers are adapted for use with more thanone type of slicer knife, and different knives can have differentattributes such as knife edge thickness. Many existing sharpenerassemblies lack the ability to account for such differences betweenknife types.

[0007] Accordingly, it would be desirable and advantageous to provide arelatively simple sharpener assembly which is always positioned forsharpening when attached to a food slicer. It would likewise bedesirable to provide a sharpener assembly operable to provide sharpeningand truing simultaneously by a single rotational motion. Further, itwould be desirable and advantageous to provide a sharpener assemblyconfigured to permit the sharpening wheel and the truing wheel to havesubstantially the same abrasiveness while still providing effectivesharpening. Still further, a sharpener assembly which enables adjustmentof the amount of sharpening which is performed would also beadvantageous.

SUMMARY OF THE INVENTION

[0008] In one aspect of the present invention a method of sharpening andtruing a rotating slicer knife of a food slicer involves providing arotatable sharpening wheel and a rotatable truing wheel on opposed sidesof the slicer knife, the sharpening wheel and the truing wheel connectedfor pivotal movement toward the slicer knife upon rotation of a handlemember. The handle member is rotated such that both the sharpening wheeland the truing wheel contact the slicer knife causing the sharpeningwheel and the truing wheel to rotate. Relative rotation between thesharpening wheel and the slicer knife results in a sharpening grainacting inward along a cutting edge of the knife and relative rotationbetween the truing wheel and the slicer knife results in a truing grainacting outward along the cutting edge of the knife. The inward actingsharpening grain provides a more aggressive grinding action as desiredfor sharpening and the outward acting truing grain provides a lessaggressive grinding action as desired for truing.

[0009] In another aspect of the present invention a sharpener assemblyfor a food slicer having a rotatable knife includes an assembly mounthead having a recessed slot, the mount head including a through hole tothe recessed. A frame having first and second spaced mount arms with aconnecting member extending between the mount arms is provided, eachmount arm including a through passage along its length. At least aportion of the connecting member is positioned within the mount headslot in alignment with the through hole. A first shaft extends throughthe through passage of the first mount arm and has a sharpening wheelconnected to a first end thereof and a second shaft extends through thethrough passage of the second mount arm and has a truing wheel connectedto a first end thereof. A handle is operatively connected to the frameconnecting member through the through hole of the mount head forpivoting the frame. The subject assembly is preferably detachablyconnected to the base of the food slicer such that the sharpening wheeland truing wheel are normally positioned on opposite sides of the knifeto facilitate sharpening as necessary by turning the handle to pivot thewheels into contact with the sides of the knife. Thus, a simple one-steprotation operation provides both sharpening and truing and there is noneed for moving the assembly to an inactive position when it is not inuse for sharpening and truing.

[0010] In yet another aspect of the invention a sharpener assembly for afood slicer having a rotatable knife includes a frame having first andsecond spaced mount arms with a connecting member extending between themount arms. A first shaft extends from the first mount arm and has afirst abrasive wheel connected to an end thereof and a second shaftextends from the second mount arm and has a second abrasive wheelconnected to an end thereof. A first biasing member is positioned on thefirst shaft for biasing the first abrasive wheel away from the firstmount arm and a second biasing member is positioned on the second shaftfor biasing the second abrasive wheel toward the second mount arm. Inthe preferred embodiment one abrasive wheel is a sharpening wheel andthe other abrasive wheel is a truing wheel and the force exerted by oneof the biasing members on the sharpening wheel is greater than the forceexerted by the other biasing member on the truing wheel. Such preferredconstruction facilitates using wheels having substantially the sameabrasiveness for both the sharpening wheel and the truing wheel.

[0011] In a further aspect of the present invention a food slicerincludes a base with a disc-like slicing knife mounted for rotation onthe base and having a peripheral cutting edge. A knife guard extendsabout a portion of the peripheral cutting edge of the knife and includesfirst and second side portions extending along respective first andsecond sides of the knife. A sharpener assembly is detachably mounted tothe base and includes a frame having first and second spaced mount armswith a connecting member extending between the mount arms, a first shaftextending from the first mount arm and having a first abrasive wheelconnected to an end thereof, and a second shaft extending from thesecond mount arm and having a second abrasive wheel connected to an endthereof. The first abrasive wheel is positioned on the first side of theknife and the second abrasive wheel is positioned on the second side ofthe knife. The first side portion of the knife guard includes a firstopen region alignable with the first abrasive wheel and the second sideportion of the knife guard includes a second open region alignable withthe second abrasive wheel. This configuration provides a slicer with asharpener assembly which is always in a ready position for sharpening.

[0012] The abrasive sharpening or truing wheels incorporated in to thesharpener assemblies may preferably be formed by a disc-shaped memberhaving a knife engaging side which includes a recessed area surroundedby an annular abrasive surface, wherein the annular abrasive surface isfrusto-conical in shape such that a central axis of the frusto-conicalannular abrasive surface coincides with a central axis of the abrasivewheel.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 is a side view of a typical food slicer;

[0014]FIG. 2 is an exploded perspective view of one embodiment of asharpener assembly;

[0015]FIG. 3 is a side view of the assembled sharpener of FIG. 2 withthe housing removed;

[0016]FIG. 4 is a bottom view of the sharpener of FIG. 3 with thehousing included;

[0017]FIGS. 5 and 6 show sharpening and truing grains respectively;

[0018] FIGS. 7-10 show the frame member of the sharpener of FIG. 2;

[0019]FIG. 11 shows an enlarged cross-sectional view of one embodimentof an abrasive wheel of the present invention; and

[0020]FIGS. 12 and 13 show alternative configurations of a blade guardadopted for use with the present invention.

DETAILED DESCRIPTION

[0021] A typical food slicing machine 100 is shown in FIG. 1. It has arotatable circular or disc-like slicing knife 102 mounted on a housing104. The knife is mounted for rotation on a fixed axis shaft. The slicer100 conventionally uses a ring guard (not shown) fastened thereto forthe protection of the cutting edge of the slicing knife 102. The slicer100 includes a cover plate 108 which is placed over the knife 102 andring guard so that only a small portion of the knife blade is exposed.The slicer also includes a gauge plate 110 used to guide the food to besliced and alter the thickness of the slices. The food is supported oncarriage 112 which reciprocates in front of the blade.

[0022] In a typical embodiment of the present invention, a sharpenerassembly which is mountable on a food slicer and a base assembly isprovided. The sharpener preferably includes two abrasive stones whichopposingly engage the front and rear sides or faces of the knifesimultaneously to grind and hone a fine edge on the knife. The mainabrasive stone is on the back side of the knife, i.e., the side oppositethe food, and comprises a circular or disc-shaped abrasive stone mountedfor rotation on a shaft. A similar abrasive stone carried on anothershaft acts as a truing stone and comes into contact with the front sideof the knife to debur the sharpened knife edge.

[0023] An exploded perspective view of a sharpener assembly inaccordance with one aspect of the present invention is shown in FIG. 2and includes a handle 10, a handle shaft 12, a housing 14, a mount head16, a frame 18, and a mount post or shaft 20. The mount head 16 includesa recessed slot 22, a through hole 24 which extends to the recessed slot22, and threaded holes 26A, 26B which extend laterally into the recessedslot 22. The frame 18 includes spaced mount arms 28A, 28B with aconnecting member 30 extending between the arms. Each mount arm includesa corresponding through passage 32A, 32B along its length. Each throughpassage receives a corresponding mount arm 34A, 34B to which theabrasive wheels 36A, 36B are rotatably attached. Housing 14 includes anopening 38 which aligns with mount head through hole 24 for permittinghandle shaft 12 to extend to and connect to a handle receiving hole 40in the connecting member 30 of frame 18. A bottom side of mount head 16also includes an opening 42 which receives the assembly mount shaft 20,with the mount shaft being non-rotatably connected thereto. Holes 44 inhousing 14 align with the corresponding holes 46 in mount head 16 toprovide attachment of housing 14 to the mount head 16. A leaf springtype biasing member 48 is connectable to one side of the connectingmember 30 of frame 18, such as by using aligned holes and screws.Although shown as separate attachable components, handle 10 and handleshaft 12 could be formed as an integral component with handle 10 beingmolded to handle shaft 12. It is also anticipated that handle shaft 12could be replaced with a torsion spring 12′, and use of such a torsionspring would act as a limit to the force applied by each abrasive wheelagainst the slicer knife 102 upon rotation of the handle 10 discussedbelow.

[0024] As best seen in the side elevation view of FIG. 3, whenassembled, the abrasive wheels 36A, 36B are spaced from each other so asto be disposed on opposite sides of a slicer knife 102. The free end ofassembly shaft 20 mounted in a non-rotatable manner with respect to afood slicer base, and with the opposite end of assembly shaft 20 mountedin a non-rotatable manner with respect to mount head 16, such as throughuse of a pin 21. Thus, when handle 10 is rotated in a clockwise manneras indicated by arrow 50, the frame 18 will likewise be rotated orpivoted within mount head slot 22 such that each abrasive wheel 36A, 36Bmoves toward the slicer knife 102 as indicated by arrows 52A, 52B untileach abrasive stone contacts its corresponding side of the slicer knife102 for sharpening and truing thereof. However, in the normal assembledposition with handle 10 not rotated, biasing member 48, which may be aleaf spring type member, urges the respective abrasive wheels 36A, 36Binto the non-contacting positions shown in FIGS. 2-3 via contact withthe side of the mount head 16.

[0025] Advantageously, disposed on each shaft 34A, 34B is a biasingmember 54A, 54B for urging the respective abrasive wheels 36A, 36Btoward the slicer knife 102 as they engage the respective side of theknife 102. In particular, biasing member 54A (FIG. 2) may be a springwasher disposed about shaft 34A at a location between abrasive wheel 36Aand an end 56 of mount arm 28A such that as abrasive wheel 36A contactsslicer knife 102 compression of biasing member 54A urges the abrasivewheel 36A into contact with the slicer knife 102 with a firstpredetermined force. Biasing member 54B may be a compression springdisposed about shaft 34B between an end 58 of mount arm 28B and an end60 of shaft 34B. Thus, in the illustrated embodiment biasing member 54Abiases abrasive wheel 36A away from mount arm 28A and biasing member 54Bbiases abrasive wheel 36B toward mount arm 28B. In order to facilitateuse of similar abrasive wheels 36A, 36B having substantially the sameabrasiveness, the force with which abrasive wheel 36A is urged away frommount arm 28A is preferably greater than the force with which abrasivewheel 36B is urged toward mount arm 28B, and abrasive wheel 36A acts asa sharpening wheel and abrasive wheel 36B acts as a truing wheel.

[0026] As best seen in the bottom view of FIG. 4, the pivot or rotationof frame 18 will be limited by the recessed slot 22 of mount head 16because connecting member 30 of frame 18 will contact the sides of slot22 after a predetermined amount of pivot or rotation. In order toprovide adjustment of the amount of permitted rotation of frame 18relative to mount head 16, one or more threaded passages 26A, 26B areprovided into which threaded members such as set screws 27A, 27B may bepositioned with interior ends of such set screws extending into slot 22.The set screws can be threaded further into slot 22 to reduce thepermitted rotation of frame 18 or can be threaded further out of slot 22to increase the permitted rotation of frame 18. This feature permits thesharpener assembly to be used in a larger variety of food slicers havingknives of different types or dimensions.

[0027] The abrasive wheels 36A, 36B each contact the slicer knife 102 soas to result in a preferred sharpening or truing grain as the case maybe. Referring to FIGS. 5 and 6, with abrasive wheel 36A acting as thesharpening wheel, contact between the wheel and the slicer knife 102 isshown at 62A. Arrow 64 indicates the direction of rotation of slicerknife 102 and arrow 66A indicates the direction of rotation of wheel 36Aupon contact with the slicer knife 102. The velocity vector V_(K) of theknife and the velocity vector V_(W) of the wheel combine to provide arelative velocity vector V_(R) (of the wheel relative to the knife)which provides a sharpening grain in the direction indicated by arrow68A, inward along the knife edge which make grinding more aggressive asdesired for sharpening. In FIG. 6, contact between wheel 36B and slicerknife 102 is indicated at 62B. The direction of rotation of slicer knife102 is again indicated by arrow 64 and the direction of rotation ofwheel 36B is indicated by arrow 66B. The velocity vector V_(K) of theknife and the velocity vector V_(W) of the wheel combine to provide arelative velocity vector V_(R′) (of the wheel relative to the knife)which provides a truing grain in the direction indicated by arrow 68B,outward along the knife edge which makes grinding less aggressive asdesired for truing. Accordingly, this feature also facilitates use ofwheels 36A, 36B having similar abrasive properties. It is recognizedthat the direction of the sharpening grain and the truing grain may varydepending upon the exact configuration of the knife as well as otherfactors.

[0028] An enlarged view of the frame 18 is depicted in FIGS. 7-10.Referring to FIG. 7, a perspective view of frame 18 is shown in whichthe frame is upside down relative to its position shown in FIG. 2. Inthis enlarged view it is apparent that the mount arms 28A, 28B areangled in relation to each other in order to facilitate proper contactof the respective abrasive wheel with the sides of the slicer knife 102.A lateral opening 70 is shown for receiving a pin or set screw toconnect the handle shaft 12 to the frame 18. Also shown are threadedholes 72 for securing the leaf spring type biasing member 48 thereto.

[0029] In FIGS. 8-10 line 74 represents a plane which runs parallel tothe axis of the handle shaft 12 and is used to define the angularrelationship between mount arms 28A and 28B. As shown in FIG. 8 mountarm 28A intersects plane 74 at an angle A and as shown in FIG. 10 mountarm 28B intersects plane 74 at an angle B. In one embodiment of theinvention angle A might be on the order of about 19 degrees and angle Bmight be on the order of about 6 degrees. However, it is recognized thatsuch angles could vary depending upon the exact configuration of theslicer knife 102 as well as other factors including the exactconfiguration of the abrasive wheels 36A, 36B.

[0030] With respect to the configuration of abrasive wheels 36A, 36B,reference is made to FIG. 11 showing an enlarged cross-sectional sideview of a representative abrasive wheel. As shown, in a preferredembodiment the abrasive wheel is a generally disc shaped member having aknife engaging side 76 which includes a recessed area 78 which issurrounded by an annular abrasive surface 80. Surface 80 may, forexample, include an abrasive coating of cubic boron nitride. Abrasivesurface 80 is preferably frusto-conical in shape as shown, with acentral axis of 82 of the frusto-conical abrasive surface coincidingwith an axis 84 of rotation of the wheel. Further, a line 86 extendingfrom and parallel to the annular surface 80 at a point thereabout and tothe axis of rotation 84 intersects the axis of rotation 84 at a nonperpendicular angle. In particular, angle C of such intersection ispreferably in the range of about 80 to 84 degrees. However, it isrecognized that such angle could vary depending up the exactconfiguration of the slicer knife 102 as well as other factors includingthe angular relationship between mount arms 28A and 28B.

[0031] With respect to attachment of the sharpener assembly to the foodslicer, mount shaft 20 is used as previously mentioned. The mount shaft20 includes an opening 90 at the bottom thereof for positioning on amount boss (not shown) of a food slicer base. The opening 90 (FIGS. 2and 3) and the mount boss may be appropriately configured to preventrotational movement of the mount shaft 20 relative to the mount boss. Itis recognized that other manners of connecting the sharpener assembly tothe slicer are possible.

[0032] Referring to FIGS. 12-13, a knife guard 118 is preferablyconfigured for facilitating the positioning of the abrasive wheels 36A,36B on opposed sides of the slicer knife 102. In this regard, the knifeguard 118 typically includes side portions 120A, 120B which extend alongopposed sides of the slicer knife 102. In order to provide access to thesides of the slicer knife 102, each side portion of the knife guard 118preferably includes a respective open region aligned with the abrasivewheel adjacent thereto. As shown in the side view of FIG. 12, such openregions may take the form of radially recessed regions 122A and 122B. Inanother embodiment shown in the top view of FIG. 13, the open regionsmay take the form of laterally spaced regions 122A′ and 122B′ of sideportions 120A and 120B respectively. Such configurations allow thesharpener assembly to be located in a sharpening position at all timeswhile permitting the sharpener assembly to be easily removable from thefood slicer.

[0033] Although the invention has been described and illustrated indetail it is to be clearly understood that the same is intended by wayof illustration and example only and is not intended to be taken by wayof limitation. For example, the respective functions (sharpening ortruing) of the abrasive wheels could be reversed as needed dependingupon the knife configuration and the mounting location of the assembly.Further, a sharpener assembly could utilize a sharpening wheel ofdifferent abrasiveness than the truing wheel without departing from thebroader aspects of the present invention. Accordingly, the spirit andscope of the invention are to be limited only by the terms of theappended claims.

What is claimed is:
 1. A method of sharpening and truing a rotatingslicer knife of a food slicer comprising: providing a rotatablesharpening wheel and a rotatable truing wheel on opposed sides of theslicer knife, said sharpening wheel and said truing wheel connected forpivotal movement toward the slicer knife upon rotation of a handlemember; rotating said handle member such that both said sharpening wheeland said truing wheel contact the slicer knife causing said sharpeningwheel and said truing wheel to rotate; wherein relative rotation betweensaid sharpening wheel and the slicer knife results in a sharpening grainacting inward along a cutting edge of the knife; and wherein relativerotation between said truing wheel and the slicer knife results in atruing grain acting outward along the cutting edge of the knife.
 2. Themethod of claim 1 wherein rotation of said handle member causes saidsharpening wheel to contact the slicer knife with a first force and saidtruing wheel to contact the slicer knife with a second force, said firstforce being greater than said second force.
 3. The method of claim 1wherein said rotating step involves utilizing a torsion spring totransmit rotation of said handle to said sharpening wheel and saidtruing wheel.
 4. A sharpener assembly for a food slicer having arotatable knife, comprising: an assembly mount head having a recessedslot, said mount head including a through hole to said recessed slot; aframe having first and second spaced mount arms with a connecting memberextending between said mount arms, each mount arm including a throughpassage along its length, at least a portion of said connecting memberpositioned within said mount head slot in alignment with said throughhole; a first shaft extending through said through passage of said firstmount arm and having a sharpening wheel connected to a first endthereof; a second shaft extending through said through passage of saidsecond mount arm and having a truing wheel connected to a first endthereof; and a handle operatively connected to said frame connectingmember through said through hole of said mount head for pivoting saidframe.
 5. The sharpener assembly of claim 4 further comprising a mountpost extending from said mount head for mounting said assembly to aslicer to prevent pivot of said mount head when said handle is turned.6. The sharpener assembly of claim 5 further comprising a first biasingmember and a second biasing member, said first biasing member positionedon said first shaft between said sharpening wheel and said first mountarm for biasing said sharpening wheel away from said first mount arm,and said second biasing member positioned on said second shaft betweensaid second mount arm and a second end of said second shaft for biasingsaid truing wheel toward said second mount arm.
 7. The sharpenerassembly of claim 6 wherein said first biasing member urges saidsharpening wheel away from said first mount arm with a first force andsaid second biasing member urges said truing wheel toward said secondmount arm with a second force, said first force being greater than saidsecond force.
 8. The sharpener assembly of claim 4 wherein said mounthead slot limits pivotal movement of said frame.
 9. The sharpenerassembly of claim 8 wherein said mount head includes at least onethreaded hole extending to said slot and having a threaded memberpositioned therein for extending into said slot and contacting saidframe connecting member upon pivot of said frame, rotational adjustmentof said threaded member effecting adjustment of permitted pivotalmovement of said frame relative to said mount head.
 10. The sharpenerassembly of claim 4 wherein said handle is connected to said frameconnecting member by a shaft.
 11. The sharpener assembly of claim 4wherein said handle is connected to said frame connecting member by atorsion spring.
 12. The sharpener assembly of claim 4 wherein said firstmount arm is angled relative to said second mount arm.
 13. The sharpenerassembly of claim 4 further comprising a housing disposed between saidhandle and said mount head and said frame, said housing extending oversaid sharpening wheel and said truing wheel.
 14. A sharpener assemblyfor a food slicer having a rotatable knife, comprising: a frame havingfirst and second spaced mount arms with a connecting member extendingbetween said mount arms; a first shaft extending from said first mountarm and having a first abrasive wheel connected to an end thereof; asecond shaft extending from said second mount arm and having a secondabrasive wheel connected to an end thereof; a first biasing memberpositioned on said first shaft for biasing said first abrasive wheelaway from said first mount arm; and a second biasing member positionedon said second shaft for biasing said second abrasive wheel toward saidsecond mount arm.
 15. The sharpener assembly of claim 14 wherein saidfirst mount arm is angled relative to said second mount arm.
 16. Thesharpener assembly of claim 15 wherein said first abrasive wheel andsaid second abrasive wheel are spaced from each other to define a knifereceiving area.
 17. The sharpener assembly of claim 14 furthercomprising: an assembly mount head positioned adjacent said frame; ahandle operatively connected to said frame for pivoting said framerelative to said mount head; and adjustable means for limiting pivot ofsaid frame relative to said mount head.
 18. The sharpener assembly ofclaim 17 wherein said handle is connected to said frame by a torsionspring.
 19. The sharpener assembly of claim 14 wherein said firstabrasive wheel comprises a sharpening wheel and said second abrasivewheel comprises a truing wheel.
 20. The sharpener assembly of claim 14wherein said first abrasive wheel comprises a disc-shaped member havinga knife engaging side which includes a recessed area surrounded by anannular abrasive surface, wherein said annular abrasive surface isfrusto-conical in shape, a central axis of said frusto-conical annularabrasive surface coinciding with an axis of rotation of said firstabrasive wheel.
 21. A food slicer comprising: a base; a disc-likeslicing knife mounted for rotation on said base and having a peripheralcutting edge; a knife guard extending about a portion of said peripheralcutting edge of said knife and including first and second side portionsextending along respective first and second sides of said knife; asharpener assembly detachably mounted to said base and including a framehaving first and second spaced mount arms with a connecting memberextending between said mount arms, a first shaft extending from saidfirst mount arm and having a first abrasive wheel connected to an endthereof, a second shaft extending from said second mount arm and havinga second abrasive wheel connected to an end thereof, said first abrasivewheel positioned on said first side of said knife and said secondabrasive wheel positioned on said second side of said knife; and whereinsaid first side portion of said knife guard includes a first open regionalignable with said first abrasive wheel and said second side portion ofsaid knife guard includes a second open region alignable with saidsecond abrasive wheel.
 22. The food slicer of claim 21 wherein saidfirst abrasive wheel is normally spaced from said first side portion ofsaid knife guard and said second abrasive wheel is normally spaced fromsaid second side portion of said knife guard, said sharpener assembly ofsaid food slicer further comprising a handle operatively connected tosaid frame for pivoting said frame relative to said base so that saidfirst abrasive wheel is moved toward said first side of said knifethrough said first open region of said first side portion of said knifeguard and said second abrasive wheel is moved toward said second side ofsaid knife through said second open region of said second side portionof said knife guard.
 23. The food slicer of claim 21 wherein saidsharpener assembly of said food slicer further comprises a mount headpositioned adjacent said frame, a handle operatively connected to saidframe for pivoting said frame relative to said mount head, andadjustable means for limiting pivot of said frame relative to said mounthead.
 24. The food slicer of claim 21 wherein said sharpener assembly ofsaid food slicer further comprises a first biasing member positioned onsaid first shaft for biasing said first abrasive wheel away from saidfirst mount arm, and a second biasing member positioned on said secondshaft for biasing said second abrasive wheel toward said second mountarm.
 25. The food slicer of claim 24 said first abrasive wheel comprisesa sharpening wheel and said second abrasive wheel comprises a truingwheel, and wherein said first biasing member urges said sharpening wheelaway from said first mount arm with a first force and said secondbiasing member urges said truing wheel toward said second mount arm witha second force, said first force being greater than said second force.26. The food slicer of claim 25 wherein an abrasiveness of said firstabrasive wheel is substantially the same as an abrasiveness of saidsecond abrasive wheel.
 27. The food slicer of claim 21 wherein saidfirst mount arm is angled with respect to said second mount arm.
 28. Thefood slicer of claim 21 wherein said first abrasive wheel comprises adisc-shaped member having a knife engaging side which includes arecessed area surrounded by frustoconical abrasive surface, a centralaxis of said frusto-conical abrasive surface coinciding with an axis ofrotation of said first abrasive wheel.
 29. An abrasive sharpening ortruing wheel installable in a sharpener assembly of a food slicer, saidabrasive wheel comprising a disc-shaped member having a knife engagingside which includes a recessed area surrounded by frusto-conicalabrasive surface, a central axis of said frusto-conical abrasive surfacecoinciding with a central axis of said abrasive wheel.
 30. The abrasivesharpening or truing wheel of claim 29 wherein a line extending fromparallel to said frusto-conical abrasive surface at a point thereaboutto said axis of rotation intersects said axis of rotation at an angle inthe range of about eighty to eighty-four degrees.
 31. The abrasivesharpening or truing wheel of claim 30 wherein said angle is abouteighty-two degrees.